Roy Keane has stated Celtic’s mindset needs to change after they were thumped 7-0 by Barcelona.

The outspoken pundit and Manchester United legend also slammed Rangers for being “one of the worst teams” the club have field in the wake of their Old Firm hammering.

Prior to the Bhoys losing their Champions League opener to Barcelona at the Nou Camp, they had beaten the Gers 5-1 in the Old Firm derby.

ITV pundit Keane gave his verdict on the Scottish giants in the wake of Celtic’ pasting in Spain on Tuesday.

“On one hand we’re being told Celtic are a great club,” Keane told ITV Sport as posted by Bench Warmers. “Great traditions, great history, and then they go and lose 7-0 to Barcelona and people say these things happen and it’s acceptable.

“The previous weekend they won 5-1, played against Rangers one of the worst Rangers teams I have seen in a long time, who finished with ten men for the last 15-20 minutes, so [I don’t agree with] that idea that they were tired as well.”

Ex-Celtic man Keane captained Manchester United to the European cup when Sir Alex Ferguson’s side won the famous treble in 1999.

Keane felt Brendan Rodgers’ side could have done better, as he lambasted the players mindsets for celebrating when they qualified for the Champions League group stages.

“A lot of these players for Celtic are international players,” said Keane “It’s not Altrincham it’s Celtic and you have got to do much better.

“I think again it’s a case of changing the mindset, I don’t necessarily mean the game against Barcelona, but the qualifying games when they were scraping through and celebrating like they’ve won the bloody thing.”

Barca forward Lionel Messi scored a hat-trick, with Celtic striker Moussa Dembele having his penalty saved by Marc-André ter Stegen in the first-half with the score at 1-0.

A brace from Luis Suarez in the second-half, including goals from Neymar and Iniesta made it a nightmare start for Rodgers’ side in their opening 2016/17 Champions League campaign.